Passenger vehicles often include electric batteries for operating features of a vehicle's electrical and drivetrain systems. For example, vehicles commonly include a 12V lead-acid automotive battery configured to supply electric energy to vehicle starter systems (e.g., a starter motor), lighting systems, and/or ignition systems. In electric, fuel cell (“FC”), and/or hybrid vehicles, a high voltage (“HV”) battery system may be used to power electric drivetrain components of the vehicle (e.g., electric drive motors and the like).
In certain designs, battery systems included in a vehicle may include one or more sections. For example, a vehicle battery system may include a battery pack that comprises one or more sections of battery cells, such as many current battery systems for electric vehicles, including rechargeable energy storage systems (RESS) for extended-range electric vehicles (EREV). The cells in such batteries may be damaged by overcharging or undercharging such cells.
Many battery systems for electric vehicles therefore include upper and/or lower voltage limits to prevent such cell damage. Such voltage limits, however, are typically static and are applied by utilizing a temperature-based look up table. Moreover, such voltage limits typically do not utilize information about the variation in voltage from cell to cell or section to section.
The present inventors have therefore determined that it would be desirable to provide methods and apparatus for adjusting the voltage limits of a battery, such as an electric vehicle battery, that overcome one or more of the foregoing limitations and/or other limitations of prior art.